OBJECTIVE: To quantitatively evaluate the changes in the soft palate (SP) by sleep videofluoroscopy (SVF). DESIGN: Retrospective analysis. SETTING: Academic tertiary referral center. PATIENTS: A total of 63 consecutive patients with snoring or sleep apnea (53 with obstructive sleep apnea [OSA] and 10 simple snorers). INTERVENTIONS: All the subjects underwent SVF and nocturnal polysomnography. Sleep videofluoroscopy was performed before and after sleep induction by intravenous injection of low-dose midazolam (2 mg per person) and was recorded during 3 kinds of events: awake, normoxygenation sleep, and desaturation sleep events. MAIN OUTCOME MEASURES: Changes in SP length and the angle between inspiratory and expiratory efforts in each group were evaluated according to sleep events; changes in the SP was assessed according to obstruction sites and severity of OSA. RESULTS: Desaturation sleep events were detected in all patients with OSA but not in simple snorers. In awake events, inspiratory efforts increased the length and angle of the SP in patients with OSA but not in simple snorers. Elongation and angulation were greatest during desaturation sleep events and least during awake events. In normoxygenation events, changes in the SP were significantly larger in patients with OSA than in simple snorers (P < .01 for SP length; P = .03 for SP angle). Elongation of the SP was the biggest in SP-type obstruction. CONCLUSIONS: Sleep videofluoroscopy quantitatively showed that the SP was considerably elongated and angulated in patients with OSA even in an awake state. It is an easy way to measure the SP changes and may be a useful technique to differentiate OSA from simple snoring with short examination time.